Adenocarcinoma of the Urethra With Mucinous Features

Primary adenocarcinoma of the female urethra is a rare malignancy. Previous studies hypothesize multiple origins, including periurethral glands or intestinal metaplasia. We report a case of a 60-year-old white woman with adenocarcinoma of the urethra who initially presented with obstructive voiding complaints secondary to a urethral mass. Wide local excision revealed invasive adenocarcinoma of the urethra with mucinous features. There was intestinal metaplasia adjacent to the tumor, as well as separate identification of intestinal metaplasia along the urethra. Ultimately, the patient underwent radical cystectomy with ileal conduit urinary diversion with no evidence of recurrence, indicating the role of early identification and surgical intervention for such cases.Key words: Urethral adenocarcinoma, Urethra, Skene gland, Genital tract tumor, Radical cystectomyCarcinoma of the urethra in women is an uncommon malignancy, accounting for approximately 0.02% of cancers in women.^1,2 Of the urethral cancers, 70% are squamous cell, 20% are transitional cell, and 10% are adenocarcinoma.¹ Primary urethral adenocarcinoma in women is a rare malignancy of unclear origin. It has been divided into two primary histologic subtypes: clear cell and columnar/mucinous (“intestinal”).³ The histologic appearance of columnar/mucinous-type adenocarcinoma is similar to colonic and endocervical malignancies.⁴ However, clear-cell adenocarcinoma is rare and may histologically resemble genital tract tumors in women.^2,4 Previous studies have alluded to the origin of urethral adenocarcinoma in the periurethral Skene glands, as these tumors were known to stain positive for prostate-specific antigen (PSA).^5,6 Other studies have proposed a different pathway after noting that chronic irritation of the urethral mucosa can lead to metaplasia into intestinal tissue, or urethritis glandularis.⁶ Although a PSA-negative adenocarcinoma does not necessarily rule out a periurethral Skene gland origin, tumors arising in this urethritis glandularis pathway are typically PSA negative.^7,8 Clear-cell carcinoma has been postulated to originate from a third pathway based on a different morphology and staining pattern. With regard to location, proximal tumors are typically the adenocarcinoma type and have a poorer prognosis than distal squamous cell tumors.⁴ Urethral adenocarcinoma typically presents with vague symptoms leading to discovery of more advanced tumors at the time of presentation. Delayed presentation has made standardization of treatment difficult to determine in the majority of patients.²